Fuel-cell separator, production of the same, and fuel cell

A fuel-cell separator is formed with a mixture composition of a thermoplastic resin and graphite particles and is provided with grooves for moving fluid, and has a gas permeability coefficient in a range of not less than 1x10mol/m.Pa.s and not more than 1x10mol/m.Pa.s, a volume specific electric resistance in the thickness direction in a range of not less than 1 m OMEGA .cm and not more than 50 m OMEGA .cm, and a density in a range of not less than 1.8g/cm and not more than 2.1g/cm, which is uniform throughout the grooves and ribs between the grooves. The molding (2) is carried out by preheating a die to a temperature not lower than a melting point of the thermoplastic resin (6), filling the mixture composition (1) in a heated state into a cavity of the die, melting and compressing the mixture composition uniformly at a predetermined pressure for forming, and cooling the same to a temperature lower than a heat deflection temperature of the thermoplastic resin while the pressure remains applied to the die. This provides a fuel-cell separator having a high conductivity, high uniformity of quality in grooves and ribs, a great strength, and a shorter molding cycle time, provides a method for producing the foregoing separator, and provides a fuel cell employing the foregoing separator.